Cementation-furnace.



WW f w F. GIOLITTI. GEMENTATION FURNACE. APPLICATION FILED 80?.17 1911.

Patented June 17, 1913.

[nwenimr v TlNTTEE sTAT ATET FEDERICO GIOLITTI, OF TURIN, ITALY,ASSIGNOB TO SOCIETA ANONIMA ITALIANA GIO. ANSALDO ARMSTRONG & 00., OFGENOA, ITALY.

CEMENTATION-FURNACE Application filed November 17, 1911.

To all whom it may concern:

Be it known that I, Fnonnioo GIoLrr'rI, a subject of the King of Italy,residing at No. 105 Corso Vittorio Emanuele, Turin, Italy, have inventedcertain new and useful Improvements in Cementation-Furnaces, of whichthe following is a specification.

This invention has for its object to pro vide an improved furnace moreespecially designed for use in carrying out a process for theeei'nentation of steel articles based on the simultaneous use of solidcarbureting substances (for instance granulated wood charcoal) andgaseous carbureting substances (for instance carbon monoxid, carbondioXid, etc.)

The invention consists in the features hereinafter described and moreparticularly pointed out in the claim.

The improved, furnace may be heated with any desired or convenient fuelin each case, for instance by generator gas, water gas, heavy oils, etc.

The constructional details of the 1m proved furnace may be varied withinwide limits to suit the fuel employed and the refractory materialsavailable.

One form among a possible great variety of the improved furnace isillustrated by way of example in the accompanying drawings in which onlyso much is shown as is necessary for understanding the invention.

Figure 1 is a view partly in vertical section through the axes of themuli les and partly in side elevation showing the improved furnace withauxiliary apparatus in position during the cementation process. F 2 is adetail on an enlarged scale.

In each muflie which is made of refractory material, there is placed acylindrical crucible A of soft steel having an outside diameter about 10to 20 millimeters smaller than the inside diameter of the mufiie. To thebottom ring is fixed a cast iron chute B of peculiar form closed at itslower end by a valve Q.

A steel part C for the entrance of the carbureting gas extends through astuffing boX in the wall of the chute. The carbureting gas enters by thepipe D which has been screwed during the cementation) upon the center ofthe part 0. The latter part is connected to the hollow cast steel casingE Specification of Letters Patent.

Patented June 17,1913.

Serial No. 660,878.

designed to support the articles to be ccmented by means of a disk Fcomposed of steel and refractory materials.

The carbureting gas after passing through a hole formed along the aXisof the part C, arrives in a small distributer (shown in Fig. 2) locatedin the interior of the device E. The pipe 0 of the gas distributor is incon neetion with the gas inlet at C, and the gas issues through holes inradial arms (Z whence it passes through a plurality of holes tormed inthe disk It into the cementation chamber G. The device E rests duringthe cementation upon a plurality of projections on the bottom to whichthe chute B is fixed.

The manner in which the various operations are effected will now bedescribed, beginning with the charging of the crucible.

It is obvious that the method of charging the crucible will varyconsiderably according to the dimensions and shape of the articles to becemented, so that only certain specified examples will be given here.

It is assumed that it is required to cement cylindrical toothed wheelswhose greatest di ameter is smaller by only 100 to 150 millimeters thanthe inside diameter of the crucible. First the pipe D is unscrewed; thenall the parts C, E and F are raised by means of the plunger L of thehydraulic ram 1, said plunger engaging with said parts by means of itstruncated conical end portion M. Then the plunger L has reached the endof its stroke, and the upper face of the disk F is only about 30millimeters below the lid R of the crucible, the said lid is removed andthe wheels to be cemented are stacked horizontally one above another onthe disk F. As the wheels are being thus stacked, the supportingapparatus C, E, F is lowered and the charging is complete when thisapparatus has reached its lowest position shown in Fig. 2.

When the articles to be cemented have been thus placed in position, thelid of the crucible is replaced, and then the bottom discharging spout Nof the receptacle G is introduced through the central aperture B (Fig.l) in the said lid. This receptacle 0 is full of still hot (about 900degrees centigrade) granulated charcoal discharged from the cruciblethat has served for the previous cementation.

The receptacle 0 may be easily moved over the muffie by hanging it on apivoting arm by means of pulley tackle.

When the receptacle 0 has been placed in position as described, thevalve closing the bottom aperture N is opened gradually to allow the hotgranulated charcoal to run out and fill all the interstices between thearticles in the crucible.

lVhen the crucible has been filled with granulated charcoal up to about2 to 3 centimeters below its top edge, the valve of the spout N isclosed, the receptacle O is raised, the central aperture in the cruciblelid is closed, the plunger L is lowered, and the pipe D is screwed tothe part G. Then carbureting gas is passed gradually through the pipe Dinto the distributer E whence it passes into the crucible, whereupon thecementation proceeds without requiring any attention other thanobserving and regulating the current of gas and the temperature.

The gases passing out of the crucible through the pipe I) on the lid,may be collected for re-use (after suitable treatment) in subsequentcementations.

After the cementation has proceeded in the manner above described forthe requisite time, the current of carbureting gas is shut off, the pipeD is disconnected and the crucible is emptied by first discharging allthe granulated charcoal therefrom through the valve Q into thereceptacle 0 beneath. hen this has been done, the lid R- is removed, andthe plunger L is raised until it engages the end cone M in the cavity ofthe part G. Then the hydraulic ram 1 is further operated to raisegradually the supporting device C, E, F, with the cemented articlesresting thereon. After this, a workman standing on the furnace near thetop opening of the mufile, has merely to take off the cemented articlesas they reach the said opening, and to place them atonce into thetempering receptacle also located on the -15 furnace, if it is desiredto subject them to a double tempering, otherwise he places the articlesin the hot ashes. As soon as the furnace has been emptied of all thecementet articles it may be charged anew for a fresh 5O cementingoperation.

Having now described my invention what I claim as new and desire tosecure by etters Patent is In a cementation furnace, a mutl'le in whichthe articles to be cemented are packed in a solid carbureting medium, ahollow casing upon which the articles to be cemented are placed, meansadapted to raise and lower the hollow casing, a gas distributing devicewithin said hollow casing, and a perforated plate forming the top ofsaid hollow casing.

In testimony whereof I affix my signature in presence of two witnesses.

FEDERICO GIOLITTL l'Vit-nesses Gr. B. ZANARDO, DIULIO NARDONI.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, I). G.

